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A house has well-insulated walls 19.5 cm thick (assume conductivity of air) and area 410 m2, a roof of wood 5.5 cm thick and area 280 m2, and uncovered windows 0.65 cm thick and total area 33m2. (a) Assuming that heat is lost only by
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- One easy way to reduce heating (and cooling) costs is to add extra insulation in the attic of a house. Suppose a single-story cubical house already had 15 cm of fiberglass insulation in the attic and in all the exterior surfaces. If you added an extra 8.0 cm of fiberglass to the attic, by what percentage would the heating cost of the house drop? Take the house to have dimensions 10 m by 15 m by 3.0 m. Ignore air infiltration and heat loss through windows and doors, and assume that the interior is uniformly at one temperature and the exterior is uniformly at another.arrow_forwardFor the human body, what is the rate of heat transfer by conduction through the body's tissue with the following conditions: the tissue thickness is 3.00 cm, the difference in temperature is 2.00 , and the skin area is 1.50 m2. How does this compare with the average heat transfer rate to the body resulting from an energy intake of about 2400 kcal per day? (No exercise is included.)arrow_forwardAt 25.0 m below the surface of the sea, where the temperature is 5.00C, a diver exhales an air bubble having a volume of 1.00 cm3. If the surface temperature of the sea is 20.0C, what is the volume of the bubble just before it breaks the surface?arrow_forward
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- (a) Calculate the rate of heat conduction (in W) through house walls that are 11.5 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is 150 m2 and their inside surface is at 20.0°C, while their outside surface is at 5.00°C. Answer _________ W (NO scientific notation ONLY Real Number) (b) How many 1 kW room heaters would be needed to balance the heat transfer due to conduction? (Round your answer to the next whole integer.) Answer__________ 1 kW room heaters (NO scientific notation ONLY Real Number)arrow_forward(a) Calculate the rate of heat conduction (in W) through house walls that are 11.5 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is 150 m? and their inside surface is at 20.0°C, while their outside surface is at 5.00°C. 1560 X W (b) How many 1 kW room heaters would be needed to balance the heat transfer due to conduction? (Round your answer to the next whole integer.) 1 kW room heaters (a) Calculate the rate of heat conduction (in W) through house walls that are 11.5 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is 150 m? and their inside surface is at 20.0°C, while their outside surface is at 5.00°C. 1565.21 X W (b) How many 1 kW room heaters would be needed to balance the heat transfer due to conduction? (Round your answer to the next whole integer.) 12 1 kW room heaters now from O…arrow_forward1) The walls of a house are 16 cm thick and have an average thermal conductivity three times that of cork. The walls' surface area is 850000 cm and their inside surface is at 20°C, while their outside surface is at 7°C. (Thermal conductivity of cork is 0.036 W/m°C). Calculate, ) The rate of heat conduction through house walls: () The amount of heat conducted in Joules, in 4 min: 2) A spherical infrared heater of radius 6.5 cm and an emissivity of 0.72 radiates 0.58 kW of power. Given, Stefan's constant = 5.67x10 8 Wm-K4. Calculate. Temperature of the heater in Celsius:arrow_forward
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